About FoilKraken
FoilKraken is an independent, fan-run site for trading card collectors and players. We answer one question better than anyone: is that booster box worth opening, or should you hold it? We also track prices for every card and sealed product, send free price alerts, and help you see what it costs to finish a set.
We cover One Piece Card Game, Union Arena and Gundam Card Game, with more games on the way.
Where the prices come from
US prices are TCGplayer market prices; European prices are Cardmarket trend prices from Cardmarket's public price guide. Both are collected once a day. We keep our own price history from the day we start tracking each card, so charts grow over time.
How Open or Hold works
For each booster box, we model what's inside using community pull-rate studies (case openings and collector data), because manufacturers don't publish odds. Then we “open” 10,000 virtual boxes using today's prices. That gives the average value, the typical box (half do worse), and the chance a box is worth more than it costs sealed. Every estimate shows its sources and a confidence level. Read the details on any booster box page.
What we don't do
- We don't sell cards or boxes, and we don't tell you what to buy.
- We don't sell your data. See our privacy policy.
- We don't lock price alerts or set tracking behind a paywall.
Contact
Spotted a wrong price, a missing card or a pull rate we should update? Email [email protected].